Garlic

Garlic (Allium sativum L.) has been used for culinary and medicinal purposes by many cultures for centuries (1). Garlic is a particularly rich source of organosulfur compounds, which are thought to be responsible for its flavor and aroma, as well as its potential health benefits (2). Consumer interest in the health benefits of garlic is strong enough to place it among the best-selling herbal supplements in the United States (3). Scientists are interested in the potential for organosulfur compounds derived from garlic to prevent and treat chronic diseases, such as cancer and cardiovascular disease.

Summary

* Garlic (Allium sativum L.) is a particularly rich source of organosulfur compounds, which are currently under investigation for their potential to prevent and treat disease.

* Crushing or chopping garlic releases an enzyme called alliinase that catalyzes the formation of allicin. Allicin rapidly breaks down to form a variety of organosulfur compounds.

* Since cooking can inactivate alliinase, some scientists recommend letting garlic stand for 10 minutes after chopping or crushing before cooking it.

* Several different types of garlic supplements are available commercially, and each type provides a different profile of organosulfur compounds depending on how it was processed.

* The results of randomized controlled trials suggest that garlic supplementation inhibits platelet aggregation and modestly improves serum lipid (cholesterol) profiles for up to three months, but it is not known whether garlic supplementation can prevent cardiovascular disease.

* The results of a few epidemiological studies suggest that high intakes of garlic and other Allium vegetables (e.g., onions and leeks) may help protect against gastric and colorectal cancer, but it is not known whether garlic-derived organosulfur compounds are effective in preventing or treating human cancers.